Apron control for carrying scrapers



Feb.6, 1940. JD APP 2, 1s9,22"2

'APRON CONTROL FOR CARRYING SCRAPERS Filed May 51, 1938 z s heetsrsheet 1 I INVENTOR V J.D.Rap]o 3,

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ATTORN EY Feb. 194b- J. D. RAPP ,189,222

APHON CONTROL FOR CARRYING .SCRAPERS Filed May 31, l938 U 2 Sheets-Sheet 2 V Wmi V p 2s 24 INVENTOR J.D.Ra a

BY @h m .81: I ATTORNEY Patented Feb. 6,1940

UNITED S T This invention relates to a carrying scraper and. particularly to an apron for the front end of the same such as is commonly used. to aid in load ing the bowl while scraping and also to form' a dirt retaining closure for the front end of the bowl when the load is being transported.

The principal objectof my invention is to provide what I believe to be a novel arrangement for mounting and controlling the movement of the apron so that at the option of the operator,

the apron may be reciprocated. lengthwise of the bowl so as to recurringly drag dirt back into the bowl either'while scrapingr orwhile discharging if the -bowl is of the rear dump type. Also apron guiding means is provided which is so arranged that the apron when returning to a point ahead of the incoming dirt, will not tend to interfere with the natural movement of such dirt into the bowl.

A further object is to mount the apron and control mechanism entirely on the bowl of the scraper, except for a single pull cable which extends forwardly to the tractor for operation. By so doing, it is immaterial, as far as the mounting and operation of the apron is concerned, how the bowl itself is mounted for movement between scraping and dumping positions, whether the bowl dumps from thelfront or rear end, or how such dumping is eflected. i a

A further object of the inventionis to produce a simple and inexpensive device and yet one which will be exceedingly eflective for the purpose for which it is designed- These objects I accomplish by means of such 3 structure and relative arrangement of parts'as will fully appear by a perusal of the following specification and claims. l I

In the drawings similar characters of reference indicate corresponding parts in the several views:

-' Figure 1 is a sectional elevation of my improved apron mounting and control mechanism as disposed in a scraper bowLand showing the position of the apron as moving forward and down to a point ahead of the incoming dirt.

45 Figure 2 is a similar view showing the apron as moving upwardly and rearwardly.

Figure 3 is a similar view showing the apron in a closure forming position. c Figure 4 is a fragmentary top plan view of the 50 structure.

Referring now moreparticularly to the characters of reference in the drawings, the scraper bowl in which the apron is mounted-comprises side plates I and a bottom plate 2 terminating in 66 a sloping blade I disposed some distance back BN1? IOEFICEp Arron common roa i scaarnns a 1;. Barn. Turlock, Calif. Application May :1, 1m, Serial-ho. 210.81; 10 Claims (01. 37-118) of the front and of the side plates. Sinceas above stated, the particular type and mounting of the bowl has no bearing on the presentin' vention and does not aflect itsoperation, 1 deem l of bowl orscraper as a whole. I a we p The front apron comprises a plate; lhaving* a slightdownwardslope or curvature to the rear, and which extends nearly, the full'distanoe between the side plates I. The apron plate is provided with side wings ig'lhe apron iarisidly connected to and depends from longitudinally extending side beams Ol arms 6 which slidably it project through guide and supporting sleeves I. These'are rockably mountedon a cross shaft 8 supported from the bowl adjacent the top thereof and well toward its rear 'end. Rollers 9 are pref-v erably mounted on the sleeves toengage the sides of the arms and reduce any tendency of lateral binding. l

Supported from the apronin front and at} the sides (thereof intermediate its top 1 and bottom are rollers it. These are spaced to fit between the side plates l and are adapted to ride ontrack it unnecessary to show any such particular type sections mounted on saidplates inside the bowl.

One such track 7 section comprises upwardly and rearwardly sloping, rails ii in having their inception at the lower edge ofcplates I some distance ahead of blade I and extending tothe top of said plates. Said rails are then bent to, extend rearwardly along the top of the side plates as far as the sleeves l. p I. l l

Another track section comprises r i2 extending forwardly along thetop of plates I from a point in front of the rails I l a greater distance than the diameter of rollers III, saidrails l2 being then bent down with a forwardslope to a termination well clearof the ground. The gap formed between each pair of rails II and I2 is normally bridged by a switch rail i3 hinged; on the rail I2 for upward opening movement and closing down of itself against railj i I. i

A third track section comprises rails ,ll substantially horizontal though having ra slight upward slope to the rear. 7 These are disposed ahead of the sloping portionof railsii and below rails If some distance, being spaced from rails H 1 a distance greater than the diameter of rollers III. I The gap between corresponding rails is closed by an upwardly opening switch rail it hinged on rail land also closing of itself' against rail H. The rails ll at their forward end terminate in front of blade [and at a (1187-. tance from the ground greater than the depth of the apron from therollersto' its lower edge.

In operation, it will be seen that if the rollers ll drop ofl the front end, of either the rails I 2 or I, the apron will then fall of its own weight to the ground, the supporting sleeves 7 rocking on the shaft 8. The apron will then occupy a position some distance in front of the scraper blade as indicated in dotted lines in Fig. 1. Rearward movement of the apron from that position until it contacts the scraper blade as shown in Fig. 3 and as induced by a pull on the arms 8, may take place without any restriction against movement either up or down as the ground contour may determine. This is because the rollers during this movement are not engaged with any rails and their'vertical or longitudinal movement is therefore not limited to any definite path.

When the-apron engages the scraper blade in closure forming position, however, the rollers 10 then engage the adjacent lower portion of the rails II on their forward faces, and a further rearward pull 'on the arms 6 causes the apron to both lift andmove rearwardly as the rollers follow said rails. As the rollers engage the switch rails I! from underneath, they lift the sarneas shown in Fig. 2, and continue up without interference. The same is true when the rollers reach and engage the upper switch rails'l3, said switch rails yielding to allow the rollers to move along the upper horizontal portion of the rails II as indicated in Fig. 2.

In this manner the dirt is engaged at. the

' scraper blade or from ahead of the same, and is both raised and movedrearwardly in the bowl. The dirtis thus positively shoveled into or toward the rearv portion of the bowl and the front end of the same is relieved of a corresponding portion of the load and scraping and loading is made easier. .While the rails ll guide the apron against downward movement while being raised, they'do not prevent direct upward movement of the apron if necessaryfor the same to yield upwardly' somewhat as it against amass of dirt.

When itgis desired to return the apron to its initial forward positionafter being advanced, it will be seen that the apron cannot move through the same path (the sloping portion of rails I I) and contact the dirt in the bowl on account of the closed switches. The rollers are therefore shunted onto the rails 12, which maintain the apron raised until it is well clear of the ground and dirt and until said apron drops off the rails in front of the dirt being scraped up. The intermediate rails I l are for the purpose of allowing the apron to be reciprocated through a shorter endless path of movement if. desired, .andalso enables the apron to be held in a definite position is being pulled back above and in front of the scraper blade, as indicated in dotted lines in Fig. 3.

The apron is moved on its rearward or working stroke by a single pull cable l6. Ihis extends from a power drum on the tractor to which the scraper is connected to one pulley of a sheave block l1 mounted on one of the sleeves I. The

cable then extendsforwardly and about a pulley- I8 mounted on top of the apron on the adjacent side and then back to and about the other pulley of the block II. The cable then preferably extends by means of direction changing pulleys I9 to and about pulleys 20 and 2| on the other sleeve I and the apron on the opposite side respectively, to a final dead end on the apron as shown'in Fig. 4. The point of direct pull from the tractor being taken at the supporting sleeve, such pulling does not'tend to exert any actual lifting action on the apron which would affect or interfere with its movement along the rails or with its otherwise unrestricted vertical movement; the normal overbalancing weight of the apron tending to hold the same down and engaged with the rails. Movement of the apron on its return or idle stroke is preferably imparted thereto by suitable spring means applied to the arms 8. This may be done in various ways. In the present instance. I have shown spiral springs 22 mounted in connection with and inside cable drums 23 mounted on the outside of the bowl near the front. Separate cables 24 wound on these drums extend rearwardly and are attached to the arms 6 rearwardly of the sleeves as shown at 25 in Fig. 4. The springs areapplied to the drums and the cables are wound on the latter in such a manner that rotation of the drums as induced by the springs tends to wind the cables thereon. As the apron and its mounting arms are moved rearwardly and the cables are payed out from the drums, the springs become wound up, so that they have ample, strength-to pull the apron forwardly through its entire stroke,

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein. 1, While this specification sets forth in detail the present andpreferr'ed construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from, the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful .and desire to secure by Letters Patent is:

' 1. In a scraper, a bowl having side plates, a front apron movable between the plates, means mounting the apron for movement both lengthwise and vertically of the bowl, means to pull the apion rearwardly and means to move the apron forwardly; said apron mounting means comprising an arm rigid with and projecting rearwardly from the apron, and a sleeve mounted on the bowl for rocking movement in a vertical plane and through which the arm slidably projects, and said apron pulling means including a pull cable extending rearwardly from a point of pull ahead oi the bowl, a pulley on the sleeve about which the cable passes and then extends for wardly and a connection between the apron and said forwardly extending portion ofthe cable.

2. In a scraper, a bowl having side plates and a scraping blade between the plates rearwardly of the front end thereof, a front apron disposed between the plates, for movement both lengthwise and vertically of the bowl, means to pull the apron rearwardly,

means tomove the apron forwardly, rails on the means mounting the apron supporting railson the plates extending forwardly 1 from in front of the first named rails and terminating at their forward end at a level above and in front of the lower termination of the fir t named rails and at a height above the bottom of the bowl greater than the depth of the apron below the elements, the rear end of said other rails being spaced from the first named railsa distance suflicient to allow the elements to pass therebetween, and upwardly movable switch rails hinged at the rear end of said other rails and extending rearwardly to normally close the gap between the rails.

5. A structure as inclaim 2, with other element supporting rails arranged to deflect the apron when moving forwardly after being raised a predetermined distance and cause the same to return to a ground engaging position along a path initially above and extending to a point in front of the first named rails. a

6. In a scraper, a bowl having side plates and a scraping blade between the plates 'rearwardly of the front end thereof, a front apron disposed between the plates, arms rigid with and projecting rearwardly from the top of the apron, sleeves mounted on the bowl at the top and rearwardly of the blade for rocking movement in a vertical plane and in which the arms are slidably supported'means applied to the apron to pull the same rearwardly without interfering with rocking of the sleeves and arms, means to move the apron forwardly, rollers on and projecting from the sides of the apron, anda rail structure on the plates on the inside and in front of the sleeves and engageable by the rollers and arranged to cause the apron, when being pulled rearwardly from a position adjacent the blade, tomove both upwardly and rearwardly and to cause the apron, when moving forwardly after being raised a predetermined distance, to travel forwardly in a substantially horizontal path to a between the plates, arms rigid with and projecting rearwardly from the top of the apron, sleeves mounted on the bowl at the top and rearwardly of the blade for rocking movement in a vertical plane and in which the arms are slidably supported means applied to the apron to pull the same rearwardly without interfering with rocking of" the sleeves and arms, means to move the apron forwardly, rollers on and projecting from the sides of the apron, roller supporting rails extending forwardly along the side plates ahead of the sleeve and adjacent the top of the plates and then sloping down to a termination adjacent the level of and in front of the blade, other rails extending forwardly from in front of the upper portion of the first named rails to a termination in front of and on a level higher than the lower termination of said first named rails, said other rails and normally closing the space between the separated rails.

8. A structure as in claim 'I, with additional roller supporting rails extending forwardly in spaced relation to the sloping portion of the first named rails below said other rails, and upwardly opening switch rails extending rearwardly from the additional rails and normally closing the space between said additional and first named rails.

'9. A structure as in claim 2, in which said means to move the apron forwardly comprises a spring, and means between the apron and spring to place the latter under increasing tension with the rearward movement of the apron.

I 10. A structure as in, claim 6, in which said means to move the apron forwardlycomprises a pair of cable drums turnably mounted on the bowl ahead of the sleeves, cables wound on the drums and extending rearwardly to connections with the arms rearwardly of the sleeves, and

springs acting on the drums to rotate the same in a cable winding direction.

JULIAN D. RAPP. 

